This invention relates to a marine propulsion unit and more particularly to an improved cowling arrangement for the power head of an outboard motor.
As is well known, most outboard motors include a power head that is comprised of a powering internal combustion engine and a surrounding protective cowling. The protective cowling serves primarily the function of protecting the internal combustion engine from the surrounding atmosphere and particularly the water which is present due to the operation of the engine in a body of water. However, it is also necessary for the protective cowling to be formed with an arrangement for permitting air to be drawn into the protective cowling for a variety of purposes, the primary of which is providing combustion air for the engine operation. A wide variety of arrangements have been proposed for permitting such air induction into the protective cowling.
Of course, the requirements for air for the engine operation give rise to a number of problems which result in compromises. Although copious amounts of air are required to ensure good engine performance, unrestricted air flow into the protective cowling can sweep water into the protective cowling and thus obviate the main purpose of the protective cowling in protecting the engine from water. In addition, most protective cowlings dispose the air inlet in the rear portion and when the watercraft is abruptly slowed, water may splash back up onto the protective cowling and enter the air inlet and cause corrosion damage to the enclosed engine.
It has been proposed to provide additional air flow to the protective cowling through the provision of an additional front air entrance to the protective cowling. These front air entrances are less likely to have water swept into them on -extreme decelerations. However, front air inlets are also more likely to ingest water during the forward travel of the watercraft than rearward air inlets.
It is, therefore, a principal object of this invention to provide an improved air inlet arrangement for the outer cowling of an outboard motor that will afford adequate air flow to the engine and which will effectively preclude the induction of water into the protective cowling.
It is a yet further object of this invention to provide an improved front air inlet arrangement for the protective cowling of an outboard motor.